Semiconductor devices are typically made in highly automated systems. Many of these systems include a central transfer chamber mounted on a monolithic platform. The central transfer chamber transfers semiconductor substrates to one or more specialized chambers or reactors located on the periphery of the transfer chamber. The specialized chambers or reactors are used to conduct the various specialized etching, chemical vapor deposition, diffusion, and annealing processes that are necessary to process the substrate. Similar such equipment is used in the manufacture of flat panel displays, as well as various optical components such as couplers, splitters, filters, array waveguide gratings, Bragg gratings, taps, attenuators, multiplexers, and de-multiplexers. Many of these processes are performed at controlled temperatures and very low pressures.